Improving the efficiency of an escapement mechanism is a constant preoccupation in the watch industry. To this end, it is generally sought to minimise dissipation of any kind in an escapement, since dissipations are difficult to control and impair the efficiency of the oscillator. In particular, dissipation through accelerations, notably due to the actual working of the mechanism or through accelerations of external origin, particularly from shocks, and dissipation through friction are harmful and difficult to control.
Currently no system of controlled dissipation is used in escapement mechanisms.
CH Patent 704457 in the name of MONTRES BREGUET SA discloses a regulator for a timepiece wheel set or striking work, for regulating the pivoting speed, about a first pivot axis, of a wheel set comprising an inertia-block pivoting about a second pivot axis parallel to the first. This regulator includes means for returning the inertia-block to the first axis. When the wheel set pivots at a speed lower than a reference speed, the inertia block remains confined within a first volume of revolution about the first axis. When the wheel set pivots at a speed higher than the reference speed, the inertia-block engages, at least on a peripheral portion thereof, in a second volume of revolution about the first axis, contiguous and external to the first volume of revolution. This peripheral portion cooperates inside the second volume of revolution with regulating means arranged to cause the braking of the wheel set and to return the pivoting speed to the reference speed, and to dissipate any excess energy. This mechanism thus describes a system for regulation to an operating or reference speed, via a device which reduces speed/torque dependency.
EP Patent 2891930 in the name of THE SWATCH GROUP RESEARCH & DEVELOPMENT LTD describes a device for regulating the relative angular velocity between a magnetic structure and a resonator which are magnetically coupled to define together an oscillator, in particular with a magnetic escapement. The magnetic structure includes at least one annular path formed of a magnetic material of which one physical parameter is correlated to the magnetic potential energy of the oscillator, the magnetic material being arranged on the annular path so that the physical parameter varies angularly in a periodic manner. The annular path includes, in each angular period, an area of accumulation of magnetic potential energy in the oscillator, adjacent to an impulse area. The magnetic material in each accumulation area is arranged so that the physical parameter of the magnetic material gradually increases angularly or gradually decreases angularly so that the magnetic potential energy of the oscillator increases angularly during a rotation of the magnetic structure relative to the resonator.